Generally, panels made of ceramic tiles, steel sheets or reinforced plastics are mainly used as a finishing material of a wall or a floor.
In recent years, as consumers' interest in interior decoration increases because of improvement in income level, the use of interior decoration materials such as various interior/exterior materials, especially natural marble, has become popular to create differentiated luxurious environments. However, natural marble has the following problems.
First, natural marble is disadvantageous in terms of cost. Marble itself is expensive as compared to other materials. Further, since marble requires special equipment or skilled stonemasons during treatment such as a carrying operation or a cutting operation, labor cost is included in the cost of marble panels and thus marble panels become very expensive. Thereby, natural marble panels are not widely used as a finishing material but are limitedly applied to some costly buildings.
Second, natural marble is disadvantageous in terms of material characteristics. Marble is heavy and brittle in comparison with other materials. Thus, in the case of forming a wall or floor using marble panels, it is likely to separate or break.
In order to solve such problems, a composite panel has been proposed, which combines natural marble with a substrate. However, the conventional composite panel is problematic in that a wet process is carried out using cement or mortar during composite-panel construction, and a sealing material such as white cement is applied between respective layers of the composite panel, so that construction efficiency is low and construction cost increases. Further, a product is placed on the cement or mortar that is provided on a construction surface for the construction, thus causing a level difference on a composite panel surface. In order to overcome the problem, a gap filling process is performed using the sealing material. In this case, resistance to a pollution source produced in daily life is lowered.